The present invention relates to an image forming apparatus and image forming method for forming images on both sides of a paper sheet in a printer unit on the basis of image data acquired by reading originals in a scanner unit.
A program scheme of a conventional image forming apparatus comprises a display control of a control panel, an input control in which the control panel is manually operated and print data is acquired from input data, and a system control section (hereinafter referred to as xe2x80x9csystemxe2x80x9d) such as a print control for printing input data.
In a double-side printing operation, the print control first effects printing on a second side of a sheet and stacks it on an automatic double-side unit (ADU). The sheet size at the time of printing is determined by the input control when an original is read. The print control effects printing on a paper sheet which is fed from a sheet cassette in which paper sheets having the sheet size determined by the input control are set.
For printing on a first side, the sheet is fed from the automatic double-side unit. After printing, the sheet is discharged to a tray or a finisher. The sheet size for the first side is the same as the sheet size for the second side on which printing has already been effected.
However, in a multiple-size double-side printing in an automatic paper selector (APS) mode, the sheet size determined by the input control at the time of reading may differ between the second side and the first side, depending on the order of originals. In this case, the following problems will arise:
(1) Where the sheet size for the second side is smaller than the sheet size for the first side, omission of image will occur on the first side.
(2) Where the sheet size for the second side is greater than the sheet size for the first side, a blank portion will form on the first side.
The object of the present invention is to provide an image forming apparatus and an image forming method capable of preventing omission of image or formation of a blank portion in multiple-size double-side printing.
In order to achieve the above object, according to the present invention, there is provided an image forming apparatus comprising: confirmation means for confirming, when an instruction has been made to read a plurality of originals with different original sizes and form read images on first and second sides of a paper sheet, whether or not the original sizes of the originals whose images are to be formed on the first and second sides of the paper sheet are the same;
first control means for performing, when the original sizes are determined to be the same by the confirmation means, a control to form an image on a paper sheet corresponding to the original size of the original for forming an image on the second side on the basis of image data of the original for forming the image on the second side, to form an image on an image formation surface of the paper sheet on the basis of image data of the original for forming an image on the first side, and to discharge the paper sheet; and second control means for performing, when the original sizes are determined to be different by the confirmation means, a control to form an image on a paper sheet corresponding to the original size of the original for forming an image on the first side on the basis of image data of the original for forming the image on the first side, to discharge the paper sheet, to form an image on a paper sheet corresponding to the original size of the original for forming an image on the second side on the basis of image data of the original for forming the image on the second side, and to discharge this paper sheet.
According to the present invention, there is also provided an image forming method comprising: a first step of confirming, when an instruction has been made to read a plurality of originals with different original sizes and form read images on first and second sides of a paper sheet, whether or not the original sizes of the originals whose images are to be formed on the first and second sides of the paper sheet are the same; a second step of performing, when the original sizes are determined to be the same in the first step, a control to form an image on a paper sheet corresponding to the original size of the original for forming an image on the second side on the basis of image data of the original for forming the image on the second side, to form an image on an image formation surface of the paper sheet on the basis of image data of the original for forming an image on the first side, and to discharge the paper sheet; and a third step of performing, when the original sizes are determined to be different in the first step, a control to form an image on a paper sheet corresponding to the original size of the original for forming an image on the first side on the basis of image data of the original for forming the image on the first side, to discharge the paper sheet, to form an image on a paper sheet corresponding to the original size of the original for forming an image on the second side on the basis of image data of the original for forming the image on the second side, and to discharge this paper sheet.
According to this invention, there is also provided an image forming method comprising: a first step of forming a print order table in a memory when an automatic paper selector mode has been set and an instruction has been made to read a plurality of originals with different original sizes and form read images on first and second sides of a paper sheet; a second step of confirming whether original size data of an original for forming an image on the first side of the paper sheet and original size data of an original for forming an image on the second side have been stored on the print order table; a third step of selecting, when each of the data has been stored in the second step, a sheet feed source of a paper sheet corresponding to the original size of the original for forming an image on the second side from a plurality of sheet feed cassettes on which paper sheets of different sizes are set in advance; a fourth step of comparing the sizes of both originals on the basis of the original size data of the original for forming an image on the first side of the paper sheet and original size data of the original for forming an image on the second side which are stored on the print order table; a fifth step of determining a discharge destination of the paper sheet with the second side, on which the image is formed, to be a finisher, where both sizes are different in the fourth step; a sixth step of selecting a feed source of the paper sheet corresponding to the original size of the original for forming the image on the first side from the plurality of sheet feed cassettes; and a seventh step of determining a discharge destination of the paper sheet selected in the sixth step, on which the image is formed, to be the finisher.